Synlett 2008(1): 116-118  
DOI: 10.1055/s-2007-1000837
LETTER
© Georg Thieme Verlag Stuttgart · New York

Synthesis of Sulfoximidoyl-Substituted Triazoles by Huisgen 1,3-Dipolar Cycloaddition

Bernhard Fügera, Genia Skluteb, Ilan Marekb, Gae Young Bolma, Carsten Bolm*a
a Institut für Organische Chemie, RWTH Aachen, Landoltweg 1, 52056 Aachen, Germany
Fax: +49(241)8092391; e-Mail: Carsten.Bolm@oc.rwth-aachen.de;
b The Mallat Family Laboratory of Organic Chemistry, Schulich Faculty of Chemistry and The Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion-Israel Institute of Technology, Haifa 32 000, Israel
Further Information

Publication History

Received 11 October 2007
Publication Date:
11 December 2007 (online)

Abstract

The reaction of alkynyl sulfoximines with in situ prepared organic azides in water-dichloromethane under reflux affords sulfoximidoyl-substituted triazoles by Huisgen 1,3-dipolar cycloaddition.

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In the reactions reported here, racemic sulfoximines were used.

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The interactions between the benzylic hydrogens and the hydrogens of the alkyl or alkoxy chain in the 1H-NOESY spectra also confirmed the molecular structures of triazole derivatives 3b-e,g,h. Although present in the crude product mixtures, the other regioisomers (triazoles 5) could never be obtained in pure form (Figure [1] ).

Figure 1

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General Procedure for the Cycloaddition ReactionUnder vigorous stirring a mixture of NaN3 (12 equiv) and the corresponding bromide (15 equiv) was heated to reflux in H2O (0.7 M) for 1 h. Then, a solution of sulfoximine 4 (1 equiv) in CH2Cl2 (0.08 M) was added dropwise. After 3 h at 100 °C under reflux and stirring, the product was extracted with CH2Cl2 and purified by flash column chromatography. As representative example, the analytical data for 1-benzyl-5-butyl-4-(N-tosyl)-(4-methylphenylsulfonimidoyl)-1H-1,2,3-triazole (3a) obtained from the reaction of sulfoximine 4a with benzyl azide are given. Colorless oil (68%); chromatography: EtOAc-pentane (1:3). 1H NMR (400 MHz, CDCl3): δ = 0.79 (t, J = 7.0 Hz, 3 H), 1.21-1.29 (m, 4 H), 2.37 (s, 3 H), 2.41 (s, 3 H), 2.76-2.85 (m, 1 H), 2.93-3.02 (m, 1 H), 5.44 (d, J = 15.5 Hz, 1 H), 5.49 (d, J = 15.5 Hz, 1 H), 7.14-7.18 (m, 2 H), 7.20 (d, J = 8.0 Hz, 2 H), 7.31-7.35 (m, 5 H), 7.80 (d, J = 8.3 Hz, 2 H), 7.98 (d, J = 8.5 Hz, 2 H). 13C NMR (100 MHz, CDCl3): δ = 13.6 (CH3), 21.5 (CH3), 21.7 (CH3), 22.7 (CH2), 23.0 (CH2), 30.5 (CH2), 52.5 (CH2), 126.5 (CH), 127.2 (CH), 128.2 (CH), 128.7 (CH), 129.0 (2 × CH), 129.9 (CH), 133.5 (C), 135.2 (C), 140.4 (C), 141.4 (C), 141.9 (C), 142.6 (C), 145.4 (C). IR (CHCl3): ν = 2959 (m), 1454 (m), 1318 (m), 1243 (m), 1096 (s), 1018 (m), 757 (s), 540 (m). MS (CI): m/z (relative intensity) = 523 (6) [M + H]+. Anal. Calcd for C27H30N4S2O3: C, 62.04; H, 5.79; N, 10.72. Found: C, 62.06; H, 5.81; N, 11.14.